My gut instinct is that this isn't about a game release, but rather GOG did a Reddit Q&A a few weeks ago where they gathered the Qs, and they're probably just about to release the As now and doing an announcement to get people talking like we are now, speculating and building interest in the big unknown...
I bet that they're going to present the answers to people's questions and possibly unveil some new announcements concerning what is in the year ahead for GOG such as potentially new information about:
- GOG Galaxy 1.2 and beyond, possibly features that are coming etc.
- Gwent progress or other announcements about it, or perhaps even a new public beta test
- Possibly a pre-announcement for the pending Galaxy release and some preview build that needs volunteer testers to bash on it before it goes out to the public (although my gut is that this is months down the line yet)
- Perhaps teasers about new publishers or new games etc. to get us excited, but probably without spilling the full details to keep it a surprise and due to NDAs etc. (such as Lucasarts/Disney, Warner Bros, Bethesda, 2K and others in the past).
They could announce a new game or something, but they don't usually make a big buzz like this just for a game release no matter how big it is, so I think something along the lines of what I said above is more likely. We'll have to wait and see...